Adaptive mode control in LMA fiber laser with a photonic lantern

In this paper, the adaptive mode control method based on a 6-port photonic lantern is presented. The structural characteristics of the photonic lantern were introduced, and the control mechanism from multi-single mode to super mode in the photonic lanterns were analyzed. The mode control experiments with the 6-port photonic lantern were conducted. We demonstrate that quasi-single mode can be achieved in large-mode field fiber by adaptively control the phase and intensity in the input ports of the photonic lantern. The output beam power in bucket (PIB) can be increased from 37% to 63%.